Ladder



Nov. -20, 1928.

s. KRAMER y LADDER Filel A1155- 5. 1926 2 sheets-sheet 'IVENTO ATTORNEYl2 Sheets-Sheet INVENTOR.

fs. KRAMER LADDER Filed Aug. s, 1926 Nov. 20, 1928.

o e e 10 0.90. o/r o o o o A T TORNEY one of the treads in detail.

Patented Nov. 20, 1928.

UNITED STATES i E 1,591,916 PATENT oFFic-E.

SAMUEL KRAMER, OF NEWARK, NEW JERSEY.

LADDER.

Application med August v8, 1926. Serial No. 188,778.

This invention relates to ladders in eneral and more especially to thosecapable o being extended in length and of either a single straight type,used in connection with an unrelated support, or the self-contained typeknown as step ladders.

It is one object of the invention to provide an all-inetal ladder havingtubular telescopic sides provided with conveniently operated extendingmeans and automatic, positive devices for retaining the parts in lengthad] ustment.

A further feature is iii the provision of a novel and practical form ofrung oi' tread intereiigaged with ladders of knock-down construction ina firm and secure manner, but capable of disassociation at will, theserungs being light although exceedingly strong and provided with nodes orcorrugations on their tread surface affording security from sliping.

p Other advantages are to be found in the economical disposition ofmetal, cheapness of construction and pleasing appearance exhibited bythe embodiments hereinafter described and shown in the accompanyingdrawings, forming a material part 0f this disclosure, and in whichFigure 1 is a front elevational view of a knock-down extension laddermade in conformity with the invention.

Figure 2 is an edge View of the same.

Figure 3 is an enlarged fragmentary longitudinal sectional view takensubstantially on line 3 3 of Figure 2.

Figure 4 is a similar sectional view taken on line 4 4 of Figurey 3.

Figure 5 is a transverse sectional View taken on line 5 5 of Figure 3.

Figure 6 is a front elevational view of a step ladder, partially brokenaway to show an incorporation of the inventiom Figure 7 is a sideelevational view of the same.

Figure Sis a fragmentary perspective view of one of the ladder sidesshowing the telescopic sections.

Figure 9 is a bottom plan view of the uppermost step drawn to anincreased scale.

Figure 10 is a fra entary sectional view showing the connection betweenthe top step and frame side.

Figure 1l is a transverse sectional view taken on line 11-11 of Figure6.

Figure 12 is a partial perspective view of The ladder in its simplestform, as shown in Figures 1 to 5 inclusive, consists of a pair ofstraight metal tubes 15, of oblong rectangular shape in cross-sectionand of any requi- 00 site length.

Each tube is sheared on one of its longer sides, as at 16, the metalbeing bent to produce outwardly inclined supports 17 arranged atsuitable uniform intervals, their upper 05 edges being disposed at rightangles with the tubes and presenting narrow openings 18 therebetween.

Removably engageable in these openin s are angular tenons 19 formedmidway te 70 width of the ends of treads or steps 20 made of heavy sheetmetal having down turned reenforcing flanges 21 along both of theirlongitudinal edges and rovided with a plurality of nodes 22 struck romthe material to ex- 75 tend above the surface, this tread being shown indetail in Figure 12.

In assembling the ladder elements the tenons 19 are passed through thespaces 18 in both of the ladder sides and pressed down until the edge ofthe supports 17 are in contact with the underside of the treads, theends of which abut the upper marginal edges of the openings 18 therebyinterengaging the elements firmly together thus maintaining the u sidesin rigid spaced relation and affording a secure support to the steps,the ensemble obviously being of knock-down construction.

It is to be noted that the tenons 19 do not extend into the spacebetween the walls of the 9o tubes which are entirely clear throughouttheir length to receive telescopically therein, similar but smallertubes 23 having a series of transverse slots arranged at intervals apartcorresponding in all respects to the openings longer than the trea s 20of the lower sec- 100 tion.

The uppermost tread 24. is of sheet metal of similar but larger crosssection than the sides 15 and in its lower side are openings 25 toreceive the extreme upper ends of the upper sections 23 which abut theinner surface of the upper wall, this wall or surface having nodes 22 ofthe type mentioned.

Centrally in the outer walls of the upper sections 23 are depressedgrooves 26 extending 110 A from their closed bottoms 27 nearly to theirtops and formed through the bottoms of the grooves, at regularly spacedintervals, are a pluralit of openings 28 bevelled outwardly at theirower edges to readily receive rounded points of detent pins 29 providedwith extending knobs and mounted in flat springs 29 fixed on the outersides of the lower sections of the ladder through which the pins ass. pA air of cords 30 are ixed to the lower closed) ends of the uppersections, these cords being partially enclosed in the grooves l26 by theadjacent walls of the lower sections through which they pass by means ofopenings 31 to engage over pulleys 32 fixed on the lower sections neartheir tops, the cords extending downwardly along the ladder sides.

The ends of the cords carry rings 33 which upon being pulled serve toraise the inner section of the ladder and these rings may be engagedwith hooks 34 fixed in the lower section as shown in Figures 1 and 2.

The extensible step ladder shown in Figures 6 and 7 is substantially ofthe same construction as that previously described, the same consistingof a pair of fiat channel sides having inreaching sheared supports 46 tocarry the treads 20, but it is noted that the supports are arrangedhorizontally parallel with the bevelled bottoms of the ladder sides andnot at right angles to the sides.

The upper elements 47 ca between them a series of treads 2.0 removab yset in slots 48 and have at their tops an overhanging plat- `form 24 asdescribed.

Pins 49 held by chains 50 pass through openings in the outer elementsand engage selectively with any of a series of corresponding opemngs 51in the upper section si es.

A pair of angular supports 52, telescopically receive upper sections 53,connected near their tops by hinges 54 with the u per elements of themain front portion of t e ladder and are provided with pins 55engageable in openings 56 in the upper elements.

The rear supports are preferably secured together by tie rods 57 and arefurther provided with pivoted hooks 58 engageable with studs 59 set inthe front lower sections 45.

Although the foregoing is descriptive of two forms ofthe invention, itwill be understood that other changes and variations may be resorted towithin the spirit of the invention in its broadest scope as included inthe appended claims.

Having thus described my invention and set forth the manner of itsconstruction and application, what I claim as new and desire to secureby Letters Patent, is

1. A ladder comprising a air of metal tubes of rectan ilar crosssectlon, said tubes having a plura ity of equally spaced transverseopenings in their adjacent sides, integral supports inclined outwardlfrom said tubes below the openings, a plura ity of metal treads, andtenons on the ends of said treads to engage said supports through theopenings.

2. A ladder comprising a pair of metal tubes, a plurality of integralspaced supports sheared from the adjacent sides of said tubes, saidsupports being inclined outwardly therefrom to present narrow openspaces at their upper edges, a plurality of metal treads and tenons onthe ends of said treads bent angularly downwardly to removably engage inthe mentioned open spaces of said supports.

This speilcationsfi ned and witnessed this twenty-ei t a o u 1926.

g y sAMtiL KRAMER.

